Sander trap



Dec. 8, 1936.

C. W. PLOEN SANDER TRAP Filed Dec. 10, 1932 2 Sheets-Sheet l C. W. PLOEN Dec. 8, 1936.

SANDER TRAP F iled Dec.

10, 1932 2 Sheets-Sheet 2 Patented Dec. 8, 1936 UNITED STATES attach SANDER TRAP Curtis W. Ploen, Chicago, Ill., assignor to Viloco Railway Equipment Company, Chicago, 111., a

corporation of Illinois Application December 10, 1932, Serial No. 646,616

'23 Claims This invention relates broadly to track sanders, and more particularly to fluid-pressure operated sanders especially designed for use on locomotive engines for applying sand to the rails for increasing the traction of the locomotive, the present I invention having special utility as a sand trap for application to steam locomotives, though it will be understood that the invention is applicable for other analogous purposes, and, therefore, finds a wide field of utility.

In track sanding devices as applied to steam locomotives, considerable difficulty has been encountered in mounting the sand traps in positions inv which the most efficient results will be attained, and in certain of the prior art devices known to me, the inlet passageway of the trap is mounted in such position as to fail to properly cooperate with the outlet passageway to form an adequate seal, which, as a consequence, results in an un desirable loss of sand due to accidental gravity flow caused by vibration of the engine in use.

Where an adequate seal has been provided in the prior art devices for preventing accidental gravity flow of sand when not needed, there resulted a clogging of the sand trap due to packing of the sand at the point of seal.

Incertain others of the prior art devices known to me it has been customary to form a plurality of sand traps as a single casting provided with separate compartmentsor chambers in which nozzles for supplying air under pressure are mounted, these chambers being designed to supply sand to the .front or rear of the several drivingwheels of the locomotive. It has been found in actual practice that, where a single casting of this type is employed, one of the chambers or sand traps tends to wearout before the others of the same casting, which necessitates discarding the entire casting. This is due to the fact ward motion most of the time and the sand traps supplying sand to the front of the driving wheels are subjected to greater use than those supplying sand to the rear of the driving wheels.

The present invention has as its principal ob jects and advantages the provision of an improved form of sand trap for insertion in the sand pipes, for delivering sand from the sand dome of a steam locomotive to the driving wheels thereof, wherein the trap serves as an adequate seal against the accidental flow of sand when not needed and yet wherein the arrangement of the. assageway in the sand trap is such as to permit of ready supply of sand under fluid pressure when desired; the provision of an improved I that with steam locomotives the engine is in forsand trap wherein the air jet or nozzle which is customarily employed for giving the initial impulse to the sand in the trap is so constructed as to permit of ready access to this nozzle; the provision of an improved sand trap of the character 5 referred to in which access to the interior of the trap may be readily accomplished for the purpose of closing off the supply of sand from the sand container or sand dome when it is desired to remove one of the nozzles for repair or replacement; the provision of an improved sand trap of the character referred to which is compact and wherein the passageway thereof for sand is provided with angularly related portions, the upper of these portions being provided with means for permitting access to the interior thereof for closing off the supply of sand where repairs are required to the air jets or nozzles; the pro vision of an improved sand trap wherein the passageway thereof has the inlet portion disposed at an angle approaching the angle of repose of the sand or other traction-increasing medium supplied; the provision of an improved sand trap of the character referred to which is provided with air jets or nozzles, one of which is mounted to impart the initial impulse to the sand in com- ,bination with means for-permitting access to the sand trap above said nozzle, also arranged as to permit of the employment of ordinary wrenches for removing and applying these elements, and wherein the sand trap may be, if desired, mounted on the boiler of the locomotive under the outer sheathing and yetbe readily accessible through a convenient opening in said sheathing, the purpose of the last referred to feature being to perunit of the installation of the sand traps according to this invention on locomotives in which the various accessories normally appearing on the outside of the sheathing are enclosed under the sheathing. 40

The foregoing and such other objects and advantages as may appear or be pointed out as this description proceeds are attained in the structural embodiments of the invention shown in the accompanying drawings, in which Figure 1 is a fragmentary elevational view of a portion of a locomotive boiler and sand dome showing one arrangement of the sand traps installed thereon;

Figure 2 is a fragmentary sectional view taken on the line 2 2 of Figure 1 looking in the direction indicated by the arrows;

Figure 3 is an elevational view of trap of this invention; and t Figure 4 is a vertical sectional view, taken on the sand the line 4- l of Figure 3, looking in the direction indicated by the arrows.

Referring now more particularly to the drawings, and first to Figures 1 and 2, there is shown in these figures a portion 5 of a locomotive boiler shell on which is mounted the sand dome or other container 8. This sand dome is of the conventional construction, and is provided with a suitable manifold outlet 1. These outlets are usually provided on both sides of the longitudinal center line of the boiler so that the side of the sand dome opposite'to that shown in Figure 2 will be provided with a duplicate outlet for driving wheels on the other side of the locomotive.

The outlet T is desirably in the form of a casting to which the shell 6 of the sand dome is conveniently secured, and cleaning plugs 8 are provided for an obvious purpose.

From the manifold outlet 7 a plurality of downwardly extending sand pipes 9, I0 and II extend, each of these pipes being provided with sand traps I2, I3 and I4, respectively, which, in turn, communicate with the sand pipe extensions 9a, Illa and No. A typical installation is shown in Figure 1, andthe arrangement of pipes is such as to adapt the same conveniently to a type of locomotive such as the Pacific type having six driving wheels, three on each side. The pipes 9a and IE0. may be extended forwardly of the first two driving wheels, and the pipe I Ia may be extended to the rear of the back driving wheel. Thus, sand may be forced under pressure into the pipes 9a and IDa for supplying sand to the track rails when the locomotive is in forward motion, and the pipe IIa will serve to supply sand behind the rear driving wheel when the engine is in backward motion.

To each of the traps I2, I3 and I4 there are provided air supply pipes I5, I6 and I! which extend to the cab of the locomotive, and the supply of air under pressure thereto may be controlled by appropriate valves located in the engine cab.

From an inspection of Figure 2 it will be observed that the pipes 9, I0, II and 9a, Illa and II a, and their respective sand traps, are all located in suitable channels in the boiler lagging indicated at I8, and thus the outer sheathing I9 of the boiler may be placed over all of the pipes, and the sand traps. This practice, which is relatively recent in American locomotives, tends to improve the outer appearance of the locomotive and, as well, brings the sand traps closer to the boiler shell where the heat of the boiler will tend to prevent freezing of the sand in the traps. This is not an uncommon occurrence where the sand traps and pipes are exposed, due to the fact that, while efforts are made to provide dry sand at all times, under certain conditions the sand does contain moisture and in extremely coldweather may freeze in the sand traps. In order to .afiord access to the sand traps for various adjustments and repairs, the outer sheathing I9 may be providedwith a suitable opening 20 over which a cover plate 2! is normally applied, secured in position by screws or bolts 22 or the like.

One of the principal advantages of this invention which will appear from the structure of the sand trap hereinafter described resides in the fact that by the general configuration of the sand trap and the location of the adjusting elements thereof they may be mounted beneath the outer sheathing and yet have the adjusting elements of said traps rendered conveniently avail able through the opening 20. With prior art deknown to me, this is not practicable, owing to the iact that one of the nozzles provided in the sand traps of prior art devices has to be reached by a specially designed elongated wrench order to remove the same, and with the sand 1 ap placed under the outer sheathing of the b iler, this would not be possible with prior art devices.

Referring now more particularly to Figures 3 and 4, which serve to illustrate the improved sand trap of this invention, I provide a sand trap in which the entire structure thereof is contained in and supported by a single casting forming a casing 23. This casing is provided with a passageway which I shall generally designate 24, the

passageway having a configuration in its various portions of such nature as to afford a seal for the sand or other traction-increasing material when the trap is mounted in a position on the locomotive boiler such as shown in Figure 1, that is to say, the trap should be installed substantially in the position in which it appears in the drawings in order to secure the best results.

The casing 23 is formed with a neck portion 25 affording an inlet 23 which is desirably connected bysuitable clamping collars or nipples 21 to the respective sand pipes 9, ID or II as the case may be. The neck 25 is provided with an externally thre ded portion 28 for receiving the respective clamping nut or collar 2?.

The inlet passageway 26 and the neck 25 contin-ue downwardly in the casting, and said inlet is provided with a portion 29 which lies at an angle to the vertical, this vertical line being indicated at AA in Figure 4.

The purpose of placing the passageway 29 at substantially the angle shown in Figure 4 is at least two-fold, namely, to bring this passageway into a position approaching the angle of repose of material which is to be used as a friction-increasring medium, and to reduce the space occupied by the entire casting, and for the purpose of permitting the proper disposition of an outlet to atmosphere provided in said passageway, indicated at 52, which will be more fully described elbow is thus afforded. At the junction of the passageways 29 and 30, that is, at the turn of the elbow, thus provided, I insert a threaded plug member St, a suitable threaded opening 32 receiving said plug. The plug on its outer end is conveniently provided with a polygonal head 33, and adjacent the inner end of said plug there is provided an annular external groove 34, and a plurality of radial openings 35 in said plug communicate with said groove. These ducts 35 in turn communicate with a threaded axial opening in the inner end of the plug into which the threaded end 36 of anair jet or nozzle 3? is inserted. This nozzle projects 9. desirable distance into the intermediate passe. sway 39 along substantially the central axis thereof so that, when air is dischargedirom said nozzle, any sand contained the elbow and the intermediate passageway 30 will be forcibly ejected ther from, and thus an initial impulse will be given to the sand con tained in the casing of the trap. This nozzle 3? is what may be termed a lifter nozzle in that it raises the sand out of the seal over the end of the intermediate passageway as desired. The nozzle 37, due to the fact that it is normally covered with sand, has a relatively large bore 38, for the purpose of preventing cloggingof this nozzle. However, a regulation of the air supply to this nozzle must be provided, and, for this purpose, the casing, along the lower portion of the neck 25, is provided with an air header or chamber 39, a duct 40 serving to establish communication between said air header or chamber 39 and the annular groove 34 in the plug 3|. In order to regulate the amount of air admitted to the nozzle 31, a metering plug 4| is provided, threaded as at 42, into the upper end of the duct 40. This metering plug has an aperture reduced in diameter as indicated at 43 for the purpose set forth.

aperture 49 for receiving a cleaning plug 50.

This plug is at the center of the structure over the metering plug 4| so as to permit of access thereto for repair or replacement. The duct 40 extends through, and is closed by, a cleaning plug 5| which may be removed to permit of access to the duct when necessary.

It will be understood that, when it is desired to remove the nozzle 31, it is only necessary to apply a wrench to the squared portion 33 of the plug 3|, whereupon this plug may be removed, carrying the nozzle with it.

In order to prevent loss of sand in large amounts when removing the plug 3 the passageway 29, hereinbefore referred to, is provided with a laterally extending opening 52 provided with a.

flan e 53 defining what may be termed a branch.

It is definitely shown that this branch has its axis X at substantially right angles to the longi tudinal axis Y of the passageway 29 so that the axis X lies at an angle crossing the angle of repose indicated at Z of the material'contained in the trap. Of course, the angle Z is only ap proximately shown, but it is found in actual practice that the angle of repose of sand, more generally used than other substances for frictionincreasing material, assumes an angle of about 30.

The flange 53 is externally threaded, as at 54, to receive an internally threaded cap 55 for normally closing the branch 52. Before removing the plug 3|, the cap 55 is removed and, while a relatively small amount of sand will thereby be lost, a pieceof wadding or waste may be inserted at the point indicated as 55a in Figure 4. Due to into the branch 52 to close the passageway 29, and prevent the fiow of sand downwardly through this passageway to the elbow formed by the passageways 29 and 30, thus preventing major loss of sand.

It will be seen that the threads being placed on the outside of the flange 53 perform their usual the angularity of 'thebranch and the position which the trap assumes on a locomotive boiler,

it is thus impossible for moisture collecting on the threads to enter the passageway 29.

Another distinct advantage in disposing the axis Y of the passageway 29 at an angle to the vertical line AA is that this brings the squared end of the cap 55 farther away from the cleaning plug 50 and thus makes the casting more compact. Furthermore, it will be observed that this arrangement further cooperates to distribute the various elements, such as cap 55, plug. 49, plug 3|, plug 5| and the plug 59 in substantially an arcuate arrangement about the casting so that applying a wrench to one of these elements is not interfered with by another thereof as will hereinafter appear.

It will be understood that while the angularity of the branch 52 is important, in that a shortening of this branch is thus afforded, the length of the branch must be such that the distance between its outer margin 52a and the abutment 54!; serves to prevent the free flow and consequent major loss of sand from the passageway 29 when the cap 55 is removed.

The intermediate passageway 39 extends upwardly at such an angle that it co-operates with the passageway 29 to form a seal which, by virtue of the cohesion of the sand or other tractionincreasing material against the walls of the passage-ways, acts as a seal to prevent the free gravity flow of the sand out of the trap. Ordinarily when the engine is at rest, the sand will assume approximately the angle of repose indicated by the dotted line B in the passageway 30, but will, due to vibration of the locomotive, tend to level off to a more or less horizontal position such as indicated by the line C. In any event, even though there may be a. tendency for a small amount of sand to leak from the outer edge 30a of the intermediate passageway, this amount of sand is relatively small and does not interfere with the efficient operation of the device. It is to be observed that the passageway-30 is provided with a liner 51 of some relatively soft metal, such as lead, babbitt, or the like, which, while having good wear-resisting properties, will permit of re-use of the entire casting by replacement of the liner when worn out. 7 i

In order to permit cleaning of the passageway 39, and also to permit access to the outlet passageway 58, I provide a removable plug 59 threadingly engaging the opening 60, the inner surface of said plug being provided with a liner 6| of material similar to the liner 57.

It will be seen that sand receiving its initial impulse from the nozzle 31 is blown outwardly and upwardly against the cap or plug 59, whereupon it" falls downwardly into the outlet chamber or passageway 58. In order to give the sand the desired impulse through the sand pipes 9a, Illa or Ha. as the case may be, I provide an auxiliary nozzle 62 having its outlet aperture of the properly controlled size indicated at 63, directed along an axis coinciding substantially with the axis of the outlet opening 64 into which one of the sand pipes leading to the driving wheels is threaded.

,This nozzle 62 is threadingly engaged, as at 65,

with a suitable aperture in an enlarged portion 53, anda-duct 67 conveysair from the chamber 39 to the nozzle 62. In order to afiord metal within which the duct 6'! may be formed, a horizontal enlargement of the outer wall of the casing 23 is provided, as indicated at 58 in Figure 3.

From an inspection of Figure 1 it will be observed that the nozzle plug 3|, the cleaning plugs 59 and 5|, and the closing cap 55, as well as the cleaning plug 59 and retaining nut 21, are all in positions convenient for the application of ordinary wrenches thereto when it is desired to remove or apply any of these elements. In other words, no special tools are required for removing the various caps and retaining nuts, and, by the positioning of these elements in substantially radial relationship about the casting, ample room is afforded between each of themto permit of the convenient insertion of a wrench for manipulating the same. l-Ieretofore sand traps of this character have been so constructed that, for example, the nozzle 3'! or a nozzle corresponding to the same, would be screwed into a solid wall of the casing, and, in order to gain access to such a nozzle, a special wrench with a long shank was required to be inserted through the opening when the plug 59 is removed. This is not necessary under the present arrangement, inasmuch as the plug 3| may be removed and does not require any special tool other than an ordinary wrench. With the prior art devices it would be substantially impracticable to mount them under the outer sheathing of the boiler without having to remove a relatively large portion of the sheathing in order to afiord room for application of special tools. This inconvenience and undesirable feature of the prior art devices is eliminated in the sand trap of the present invention. It will be ob-.

served that it is not necessary that the plug 3! be tightened up to any particular position other than that the groove 34substantially register with the duct 40. It is not necessary to bring the bores 35 into alignment with the duct 311 in order to get air into the nozzle 31.

If it is desired to remove and clean the nozzle 62, this may be done through outlet 64 when the sand pipe is disconnected.

The opening 20 in the sheathing of the boiler may be any desired configuration, but itwill be observed from an inspection of Figurel that a substantially oval hand opening, such as shown in dotted lines in this figure, will serve adequately to afiord the necessary exposure of the parts where it is desired to make repairs or replacements therefor. It also will be noted that, when it is desired to replace a worn trap, it is not necessary that any of the portions of the other traps be disturbed. By the arrangement of suitable joints 69, '69 in the sand pipes, sections of these pipes may be removed when the sand trap is disconnected from one of the respective pipes 9, l0 and II. To prevent the loss of the sand vfrom the sand dome during such repairs, the respective one of the plugs B is removed and a piece of waste or other wadding may be inserted into the corresponding opening which becomes exposed by removal of the respective plug, thus preventing free gravity flow of the sand.

One manner of removing one of the sand traps, for example, for removing the sand trap l2, may

i be to disconnect the joint 69, applying a wrench thereto which will allow the pipe section 5a to be free from the remainder of the pipe which is perfor material, said passageway having angularly related superposed portions the axes of which form an acute interior angle, one of said portions being connected at one end to said container and being disposed at an angle to the vertical approaching the angle of repose of the material in said container.

2. A trap comprisinga casing provided with a passageway connected at one end to a container for material, said passageway having angularly related portions of which two adjacent superposed portions form an acute interior angle, one of said adjacent portions being connected at one end to said container and being disposed at an angle to the vertical approaching the angle of repose of the material in said container, and plied into said trap, an intermediate portion of lated portions for ejecting material from said casing.

3. In a sand trap for track sanders a casing provided with an outletand having an inlet connected to receive sand from a container, and a passageway in said casing provided with superposed angularly related portions forming an acute interior angle and affording a sealing elbow preventing free gravity flow of sand through the casing, one of said portions having its axis lying at an angle approaching the angle of repose of the sand flowing into said casing.

4. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having superposed angularly related portions, the axes of which form an acute interior angle, one of said portions being connected at one end to said container and being disposed at an angle to the vertical approaching the angle of repose of the material in said container, and a port in one of said angularly related portions opening laterally thereof and substantially normal thereto to permit of access thereto.

5. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having acute interior angularly related superposed portions, the upper inlet portion of which is connected to receive material from said container, a laterally disposed outlet portion substantially normal to the axis of said upper inlet portion, said upper inlet portion lying on an axis at an angle to the vertical which approaches the angle of repose of the material in said container so as to bring the axis of said outlet to an angle intersecting the angle of repose of material contained therein.

6. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having acute interior angularly related superposed portions, the

upper inlet portion of which is connected to re- 7 ceive material from said container, a laterally disposed outlet to atmosphere substantially nornzal to the axis of said upper inlet portion, said upper inlet portion lying on an axis at an angle to the vertical which disposes the axis of said outlet to intersect the angle of repose of the material in said container, and means acting in another of said angularly related portions for ejecting material supplied thereto by gravity from said upper portion.

'7. A trap comprising a casing provided with a passageway connected at one end to a container for materiaLsaid passageway having acute interior angularly related superposed portions, the upper inlet portion of which is connected to receive material from said container, a laterally disposed outlet to atmosphere substantially normal to said inlet portion, said upper inlet portion lying on an axis at an angle to the vertical which disposes the axis of said outlet so as to intersect the angle of repose of the material in said container, means for impelling material through said casing including a nozzle connected to a source of fluid pressure, said nozzle being located at the bottom of said upper portion, and a removable plug supporting said nozzle.

8. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having angular-1y related portions the upper inlet portion of which is connected to receive material from said container, said upper inlet portion lying on an axis at an angle to the vertical which approaches the angle of repose of the material in said container, means for impelling material through said casing including a nozzle connected to a source of fluid pressure, said nozzle being located at the bottom of said upper portion, and a passageway for fluid under pressure in said casing, and a removable plug supporting said nozzle and having ducts connected to said fluid passageway.

9. In a trap of the character described in con bination a casing having a passageway provided withan inlet portion disposed in normal operation on an axis at an angle approaching the angle of repose of granulated material adapted to be supplied into said trap an intermediate portion of said passageway being disposed below and at an acute interior angle to the inlet portion and communicating therewith to form an elbow, means for forcibly ejecting material from said elbow, and an outlet opening in said inlet passageway substantially normal thereto permitting access thereto above said ejecting means.

10. In a trap, a casing having a passageway provided with an inlet portion, an intermediate portion, and an outlet portion, said inlet portion being at an angle to the other portions of said passageway and disposed on an axis approaching the angle of repose of granulated material supplied to said trap, an air nozzle removably mounted at the junction of said inlet and intermediate portions, an auxiliary air nozzle mounted in said outlet portion, a cleaning opening and plug therefor adjacent to said auxiliary nozzle, a removable plug member for supporting said first mentioned nozzle, said inlet passageway having a branch normal thereto and closed by a plug located above said first named nozzle, a connection to a source of fluid under pressure on said casing between the plug supporting said first mentioned nozzle and said inlet portion of said passageway, and passageways connecting said connection to fluid pressure to both of said nozzles.

11. In a trap, a casing having a passageway provided with an inlet portion, an intermediate portion, and an outlet portion, said inlet portion being at an angle to the other portions of said passageway and disposed on an axis approaching the angle of repose of granulated material supplied to said trap, an air nozzle removably mounted at the junction of said inlet and intermediate portions, an auxiliary air nozzle mounted in said outlet portion, a cleaning opening and plug therefor adjacent to said auxiliary nozzle, a removable plug member for supporting said first mentioned nozzle, said inlet passageway having a branch normal thereto and closed by a plug located above said first named nozzle, a connection to a source of fluid under pressure on said casing between the plug supporting said first mentioned nozzle and said inlet portion of said passageway, and passageways connecting said connection to fluid pressure to both of said nozzles, said several closing plugs, and nozzle supporting plug being disposed substantially radially with respect to the center in an are about the same.

12. In combination with a locomotive boiler having .a sand container mounted thereon, and said boiler having lagging and an outer sheathing, sand traps mounted on the boiler adjacent to said sand container and beneath said outer sheathing, and means on said outer sheathing permitting access to said sand traps.

13. In a trap, a casing having an irregular passageway therethrough formed to provide an inlet portion, an intermediate portion and an outlet portion, said inlet portion being disposed on an axis lying at an angle approaching the angle of repose of granulated material admitted to said trap from above, said inlet portion having a laterally directed branch substantially normal thereto and provided with a flange having ex ternal threads thereon, a cap member internally threaded to engage the threads on said flange, for closing said opening, said branch being disposed at such an angle as to form with said passageway a seal for preventing free gravity flow of material from said branch when said cap is removed.

14. A trap comprising a casing provided with a passageway connected at one end to a container for material arranged to flow through said trap, said passageway having a normally closed branch providing access to said passageway, and means for opening and closing the outer terminal of said branch, said branch being disposed at an angle to the angle of repose of the material flowing from said container sufficient to form a seal preventing substantial flow of material from said container and said passageway through said branch.

15. A trap comprising a casing provided with an inlet passageway connected at one end to a container for material, said passageway having a portion arranged at an angle to said inlet portion and having a normally closed atmospheric connection, means for opening and closing said connection, and a depending abutment interposed between said passage and the outer margin of said atmospheric connection, the distance between said abutment and said margin being such that when said connection is opened, material from said casing will not flow through said atmospheric connection.

16. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having a portion disposed at an angle approaching the angle of repose of the material supplied from said container, and a laterally and upwardly extending branch communicating with said passageway and lying on an axis intersecting such angle of repose, an intermediate passageway lying adjacent to and communicating with said inlet passageway and forming an acute interior angle with said inlet passageway, and means in said intermediate passageway for forcibly ejecting material therefrom.

17. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having a portion disposed at an angle approaching the angle of repose of the material supplied from said container, and a laterally upwardly extending branch communicating with said passageway and lying on an axis intersecting such angle of repose, an intermediate passageway communicating with said inlet passageway and forming an acute interior angle with said inlet passageww said branch and said intermediate passageway lying in the same plane with and on opposite sides of the axis of said inlet portion.

18. In a sand trap for track sanders a casing provided with an outlet and having an inlet connected to receive sand from a container, and a passageway in said casing provided with superposed angularly related portions forming an acute interior angle and affording a sealing elbow preventing free gravity flow of sand through the casing, one of said portions having its axis lying at an angle approaching the angle of repose of the sand flowing into said casing and the other of said portions having its axis extending upwardly from the horizontal adjacent to said inlet and forming an acute interior angle with the axis of said first portion.

19. In combination with a locomotive boiler having a sand container mounted thereon, and said boiler having lagging and an outer sheathing, sand traps mounted on and against the shell of the boiler adjacent to said sand container and beneath said outer sheathing, and means on said outer sheathing for permitting access to' said sand traps.

20. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having an inlet portion disposed at an angle approaching the angle of repose of the material supplied from said container, a laterally and upwardly extending portion communicating with said passageway and lying on an axis and extending in a direction substantially opposite to that of said inlet portion so as to form an interior acute angle therwith and to thereby reduce the space occupied by said trap.

21. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having an upper portion disposed at an angle approaching the angle of repose of the material supplied from said container, and a laterally and upwardly extending portion communicating with the lower end of said upper portion, said portions being in superposed relation to each other.

22. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having an upper portion disposed at an angle approaching the angle of repose of the material supplied from said container, at laterally and upwardly extending portion communicating with the lower end of said upper portion, said portions being in superposed relation to each other, and means in said last mentioned portion for ejecting material therefrom.

23. A trap comprising a casing provided with a passageway connected at one end to a container for material, said passageway having angularly related portions of which two adjacent superposed portions form an acute interior angle, one of said adjacent portions being connected at one end to said container and being disposed at an angle to the vertical approaching the angle of repose of the material in said container, a lateral branch extending upwardly from said portion providing access thereto, a removable closure for said branch, and means below said branch for ejecting the material from said casing.

CURTIS W. PLOEN. 

